1. Technical Field
This disclosure relates to an image forming apparatus, and more specifically to an image forming apparatus including a sheet cutting device to cut a rolled sheet to a desired length.
2. Description of the Related Art
Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multi-functional devices having two or more of the foregoing capabilities. As a conventional type of image forming apparatus, an image forming apparatus is known that feeds a long-size rolled sheet (hereinafter, rolled sheet) in a certain feed direction (hereinafter, sheet feed direction) to form an image on the rolled sheet. The image forming apparatus typically has a sheet cutting device to cut the rolled sheet to a desired length by moving a cutter in a direction perpendicular to the sheet feed direction (hereinafter, width direction).
Such a conventional sheet cutting device needs to return a cutter holder holding the cutter to an initial position (home position) in preparation for the next sheet cutting. At this time, if a forward path along which the cutter moves to cut the sheet is identical to a backward path along which the cutter moves to return to the home position, the cutter contacts the already-cut sheet on the backward path, thus hampering movement of the cutter holder (so-called “cut jam”) or causing other failure.
To prevent such a cut jam or other failure, for example, JP-2009-214200-A proposes an image forming apparatus including a sheet cutting device in which the backward path of the cutter formed with the pair of circular blades differs from the forward path of the cutter. Relative to the forward path, the backward path is arranged at a downstream side in the sheet feed direction in which the sheet is fed along a sheet feed path and at a position away from a leading edge of a subsequent divided sheet upstream from the cutter in the sheet feed direction.
Specifically, after the cutter finishes the cutting operation, the cutter holder is tilted toward the downstream side in the sheet feed direction around a guide member for guiding the movement of the cutter holder. Thus, the position of the cutter moving along the backward path in the sheet feed direction is shifted to the downstream side in the sheet feed direction relative to the position of the cutter moving along the forward path. Such a configuration can prevent the cutter from contacting the subsequent divided sheet on the backward path, thus preventing a cut jam.
However, in the image forming apparatus described in JP-2009-214200-A, the cutter holder and the carriage holding the recording head are arranged independently of each other and in tandem in the sheet feed direction. As a result, the width of the image forming apparatus in the sheet feed direction is relatively large, thus resulting in an increased size of the image forming apparatus. As described above, in the image forming apparatus, the forward path of the cutter differs from the backward path, thus preventing the cutter from contacting the subsequent divided sheet on the backward path. However, the cutter holder still remains on the sheet feed path after cutting operation. As a result, the subsequent sheet cannot be fed from the rolled sheet until the cutter and the cutter holder return to the home position, thus hampering gains in productivity.
Hence, to enhance productivity while providing a compact apparatus main unit, the inventors of the present patent application have conceived an image forming apparatus having the following configuration. In the image forming apparatus, the carriage is arranged to overlap the cutter holder in a thickness direction of a rolled sheet to reduce the width of the apparatus main unit in the sheet feed direction. Additionally, relative to the forward path, the backward path is arranged so as to be retracted from the sheet feed path in the thickness direction of the rolled sheet. Thus, after the cutting of the rolled sheet, the cutter holder is movable along the backward path with the cutter holder retracted from the sheet feed path.
Such a configuration can reduce the width of the apparatus main unit, thus allowing the inkjet recording apparatus 1 to be more compact. Additionally, because the cutter holder is movable along the backward path with the cutter holder retracted from the sheet feed path, a subsequent portion of the rolled sheet can be fed while the cutter holder moves along the backward path, thus enhancing productivity.
However, in the image forming apparatus having such a configuration, because the carriage is arranged to overlap the cutter holder in the vertical direction, a movement area of the carriage in the sheet width direction (the main scanning direction) overlaps a movement area of the cutter holder along the forward path. In other words, if the cutter holder moves during movement of the carriage or the carriage moves during movement of the cutter holder, the carriage would interfere with the cutter holder. As a result, for example, if the cutter holder is abnormally stopped on the forward path, the carriage cannot be moved, thus hampering movement of the carriage to a capping position which is located at one end of the movement area of the carriage. Consequently, the nozzle faces of the recording heads might dry, thus causing an ink ejection failure or damage to the recording heads.